The weevil is a type of beetle that is known for damaging crops. Whether they damage stored grain or dried food products, or attack cotton crops, the many types of weevils can cause problems for farmers and consumers alike.

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In an effort to develop more eco-friendly control methods for the weevil, researches have discovered that different colored traps attract more sweet potato weevils than other colors.

In a study conducted by Gadi V.P. Reddy, entomologist/ecologist at Montana State University and his collaborators from the University of Guam, researchers discovered the relationship between colors and trap effectiveness while developing a trapping system for the sweet potato weevil.

First, researchers used a variety of traps that used pheromones to attract the insects with each trap being a different color.

So what color trap caught the most sweet potato weevils?

The scientists discovered that red traps are best when the weevils are outdoors and green traps are most effective when sweet potato weevils are inside warehouses, greenhouses or other covered spaces. With or without pheromone lures, green traps caught significantly more adult sweet potato weevils than traps of any other color.

The scientists don't know why color makes a difference, but they will pursue that question in future studies, Reddy said, noting that insects use chromatic cues to identify colors.

Sweet potatoes are grown in the southern United States, Guam, Hawaii, China and many other areas of the world. The sweet potato weevil, Cylas formicarius, is one of the most serious insects causing damage to sweet-potatoes in the world and without proper and effective control, weevil populations are likely to cause a huge or complete loss of sweet potato production in sweet potato growing areas.

The researchers conclude in their paper that although some control methods are effective, toxic pesticides applications are detrimental and damaging to our environment. Understanding how different color traps attract weevils may be key in controlling weevil populations.